The problem with dhai

I am giving the muse a break and since I am pretty damn sure that no one is reading all this drivel, I am going to keep myself amused by recounting something funny. And then I will laugh all by myself and feel sorry for the whole world that they are not privy to this. So here goes...

Once upon a time, in a building of six wings reclining below a hill in a place called Borvali in the northern end of a city called Mumbai, my brother got off the autorickshaw. Us Malayalees dont pride ourselves on our know of Hindi and therefore you (or rather I, since only I am reading this) are warned to look at the following exchange with kind commiseration.
The minimum fare in those days used to be Rs 7.50 which my brother was unaware of. Having got down, he fished out a Rs five note and threw it at the rickshaw driver.

The rickshaw driver now: Saahab, dhai rupiya aur ('Rs dhai please more, sir', if you want my sorry translation)

My brother fishes out another Rs 2 note and gives to rickshaw driver. Now here comes the nub: He thinks, 'dhai' means Rs 1.50.

So, we have this situation: Both rickshaw driver and brother looking at each other, each expecting the other to donate a 50 paise coin to the other. Time passes thus.

Finally, the rickshaw driver breaks the ice: Saahab, pachas paise

And my brother, paragon of generosity, says: "KEEP THE CHANGE!!!

Because all witnesses were rolling on the ground at this point, no one knows what transpired later.